Focal Nodes

Focal Nodes are intermediate targets comprising an area and a Focal Segment. Entities targeted to a Focal Node move towards its Focal Segment and are re-targeted to another object once they step into its area. In this way Focal Nodes function as intermediate objectives or ‘decision-points’ within an Entity's total journey.

You should use Focal Nodes when you want to create a subroute for a percentage of your Entities or certain Entity Types. A typical application arises when there are multiple valid paths to the same onward destination.

You can associate Focal Nodes with Availability Profiles (for more information, see "Availability Profiles" in Exits).

Setting Focal Node parameters

This procedure assumes you have already drawn a Focal Node and the 'Edit Focal Node <name>)' dialog is displayed.

To set Focal Node parameters:

Enter a name for the Focal Node in the 'Name' box (or leave it as it is if you are happy with the existing name).
In the 'Link Options' area, select one of these two options:
- Revert to final destination (Entities will proceed to wards this target or targets)
- Specify links
If you select 'Specify link', click on the 'Links' tab and add your target objects manually following the steps in Linking methods ).
If you need to test your model against required regulatory flow rates you may wish to set a maximum value for 'Flow Rate Limiting'. To do so, check the box Maximum and enter a value for people/minute in the adjacent field.
If you want to associate the object with an Availability Profile, click the 'Availability' tab.
Select an Availability Profile from the drop-down list labelled ‘Time Scope’.
If you want to apply conditions to the Availability Profile, check the box labelled ‘use condition’.
Select an option from the left-hand drop-down list:
- AND – the condition will apply only when the ‘Time scope’ settings and the conditional settings are both ‘true’.
- OR – the condition will apply when either the ‘Time scope’ settings or the conditional settings are ‘true’.
Set up your condition as described from step 4 of " To set up a Condition" in Setting up Conditions .
If you wish to apply any restrictions to the condition, click on the ‘Availability’ tab again and enter values for the following restrictions (details in Restrictions ):
- Time before action
- Minimum activity period
- Maximum activity period
- Minimum time between Actions
Entities automatically navigate towards the Focal Point of the object if and when they cannot 'see' it due to obstructions. In rare instances this may cause them to move in an unexpected or illogical manner. To remedy this, click to the 'Target Parameters' tab and uncheck 'Use focal point for navigation'.In this case Entities will navigate towards the closest point on the Focal Segment.
Click OK to save the parameters.

Setting Availability parameters

You can associate Focal Nodes with Availability Profiles, to switch them ‘on’ or ‘off’ at specific times or in response to certain conditions in a simulation. The steps are identical to those described in Setting Availability parameters .